Process for hardening varnish.



C, A. CUTLER.

PROCESS FOR HARDENING VARNISH.

APPLICATION FILED MAY 28. 1912.

1,288,6855 I PuUflltQdNm'.5,1918.

ITNESSE-S INVBNTOR FBY AT TOENEY UNITED STATES PATENT orrIoE.

CLIFFORD A. CUTLER, OF BUFFALO, NEW YORK.

PROCESS FOR HARDENING VARIVISH.

Specification of Letters Patent.

Patented Nov. 5, 1918.

Application filed May 28, 1912. Serial No. 700,255.

To all whom it may concern Be it known that I, CLIFFORD A. CUTLER,

a citizen of the United States of America,

residing at Buffalo, in the county of Erie and State of New York, have invented certain new and useful Improvements in Processes for Hardening Varnish, of which the following is a full, clear, and exact description.

In most processes of the prior art, it has been customary to employ condensing coils to cause a circulation of air used in drying. In processes of this kind. the moisture contained in the air that is used for drying, is condensed by the condensing coils and taken out of the air, thus making ,the air much drier than the ordinary atmosphere. In these processes the varnish is hardened or oxidized in air containing a great deal less moisture than the air contained in the atmosphere and, as is 'well known tothose' skilled in the artfthe wood upon which varnish is spread should not be treated to an excessive drying condition during the finishmg process. v y

In roducing my invention, I have sought,

there ore, to provide a process which shall dispense with the use of condensing coils and in which the humidity of the air may be controlled and kept proportionately the same as that of the atmosphere. This also prevents. the upper surface of the varnish from hardening before the varnish underneath can dry.

Another object of my invention has been.

to provide aprocess which may be conveniently and easily carried out in any factory, at a comparatively small initial cost and one which shall be inexpensive to operates Another object of my invention has been to provide a process in which the oxygen contained in the air, which comes directly in contact with the articles to be treated,

may be replenished without causing any substantial change in temperature of the '-air= used during the process, thus greatly decreasing the time of oxidization of' .the var- IliSl'l. r '1' Furthermore, the circulation of airin my process is in ageneral horizontal direction, so that, large surfaces, such, for instance, as

table tops will be'dried as rapidlyat' thev center thereof as at the edges .and a large,

number of. pieces may also be rapidly dried by lacing them in a horizontal position on rac s.

For the purpose of clearly describing my processes, I have shownin the accompanying drawings and described in this specification, one method of 'carryin out my invention, but it should be un erstood that other means may be employed without departing from the invention herein described.

In the drawings like characters of reference indicate like parts throughout the several views, of which:

-Figure 1 is a plan View of a kiln, em- I .bodying a preferred form of my invention.

Fig. 2 is a side sectional elevation thereof.

Fig. 3 shows an enlarged sectional view of a means for securing together the edges of two adjacent curtainsof the kiln.

Fig. 4 is an enlarged sectional elevation of the bottom edge'ofone of the curtains and shows the curtain stickin place.

Fig. 5 isa plan view of amodified form of kiln where only two curtains areemployed.

Fig. 6 is a sectional-elevation of a single curtain and shows substantially the form the curtain takes when the kiln is in operation.

Inthe' drawings, 8 represents the ceiling and 9 the floor line of any room in which my kiln is placed. Suspended from the ceiling tain' in place near the floor. Each of the curtains below the batten 12 is preferably pro f vided. with a projecting end '13 which is arranged to lie uponthe floor 9 when the curtain is in position and this projection serves the floor, even if there'be inequalities in the upper surface of the floor. Each-of the curtains 10 is provided with suitable means for raising them out of the way. Thismay be accomplished by any one of the' well known 10 means, but preferably as shown in the drawings, where 14 represents acord secured to the batten 12 at one end and extending up the outside of the curtain, through eyelets or rings 16 secured to the same at suitable 1.10;

to close the space between the curtain and intervals and over .a pulley 15, secured to the ceiling 8..

Placed within the kiln and near one of tween the radiator and the curtain and serves to deflect the air currents upwardly.

21 is a fan which preferably oscillates and which is placed in front of the radiator and operated to draw the air from the opposite A side of the kiln and force it through the said radiator. This fan may be dispensed with if desired, as there would be without it, a natural circulation of air within the kiln, but the fan is preferably employed to increase that circulation and when used it permits the employment of a smaller radiator than otherwise.

Where .the kiln herein described is employed in factories, where there is considerable draft, it is advisable to employ some means tosec-ure together the edges of adjacent curtains of the kiln. This mayv be carried out by the arrangement shown in Fig. 3, where '22 represents a post which is secured to the floor and is preferably disposed inside of the kiln and at each corner thereof. Inclosing the posts on two sides arev cent edges of the curtains 10 are placed between one of the posts and one pair of strips 23 and frictionally held in this position. The strips 23 are secured to the posts 22 by any suitable means. 25 represents a steam nozzle which is connected to the steam supply pipe 18' and provided with a valve 26. By means of this nozzle, steam may be admitted to the kiln as desired and thereby the humidity of the air may be increased.

In Fig. 5, I have shown a modified arrangement in case it is desired to place'the kiln in the corner of a room and thus employ two walls 27 of the room for two of the walls of the kiln. In some cases advantageous results may be obtained by this arrangement.

When my process is being carried out by the kiln herein described, the air contained therein is drawn across the bottom thereof and blown through the radiator by the fan 21.. This air as it passes through the radiator is heated and" is deflected upwardly by the bafiie plate 20. This air, because of its 'heated condition, as well as, because of the nasae'sei current produced by the fan, will rise to the upper part of the kiln. The heated air, as it passes across the upper part of the kiln, strikes the opposite curtain and the curtain at each side near their top and as this air is higher in temperature than that contained in the atmosphere outside of the kiln, it is cooled somewhat, which causes it to move downwardly toward the bottom of the kiln, where it is again drawn, by means of the fan and forced through the radiator, when it is again heated. The curtains of the kiln thus act as cooling surfaces but do not condense any of the moisture contained in the air.

The curtains of the kiln are somewhat porous and, some of the'air, as it strikes the upper part thereof, will pass therethrough and fresh air will be drawn in the kiln through the curtains at the bottom to take the place of that which has passed out through the top, as indicated by the arrows in Fig. 6. By this means, the oxygen in the air contained within the kiln will be replenished and the hardening of the varnish greatly increased thereby.

While I have described my process as applied to the hardening of varnish, it is, obviously, applicable to dry or harden any other liquid coating applied to wood or other materials.

Obviously, my process may be carried out by devices other than that herein shown and described and I do not wish to limit myself to the exact embodiments herein shown and 'described.

. cooled by contact with the wall of the chamber, a portion of the air, thus cooled, being forced out through its permeable wall near the top of the chamber to the external atmosphere some air from the external atmosphere being drawn into the chamber through the lower portion of ,thepermeable wall, thereby regulating the quality of the air within the chamber.

'In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

CLIFFORD A. CUTLER. Witnesses:

J. WM. Ennis, WALTER H. KELLEY. 

